bitbake: data: Handle BASH_FUNC shellshock implication

The shellshock patches changed the way bash functions are exported.
Unfortunately different distros used slightly different formats,
Fedora went with BASH_FUNC_XXX()=() { echo foo; } and Ubuntu went with
BASH_FUNC_foo%%=() {  echo foo; }.

The former causes errors in dealing with out output from emit_env,
the functions are not exported in either case any more.

This patch handles things so the functions work as expected in either
case.

[YOCTO #6880]

(Bitbake rev: f28f37220e7787721a31b659521a1c44ebea92bf)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/data.py

@@ -219,6 +219,13 @@ def emit_var(var, o=sys.__stdout__, d = init(), all=False):
 
     val = str(val)
 
+    if varExpanded.startswith("BASH_FUNC_"):
+        varExpanded = varExpanded[10:-2]
+        val = val[3:] # Strip off "() "
+        o.write("%s() %s\n" % (varExpanded, val))
+        o.write("export -f %s\n" % (varExpanded))
+        return 1
+
     if func:
         # NOTE: should probably check for unbalanced {} within the var
         o.write("%s() {\n%s\n}\n" % (varExpanded, val))